12 June 2011

Create HDR effect from just one photo

There are plenty of tutorials explaining how to create an HDR photo.
Most of them mention use of so called Auto Exposure Bracketing (AEB), a function some DSLR photo cameras don't have, or for that reason, taking three shots of the same scene using different aperture times or different exposure compensation values.

No matter how fast we shoot, if we shoot in dynamic conditions, for example photographying a car that moves fast, or tops of trees moved by strong wind, or we take photos from a train window... we will almost always end up having three photos with objects that are not in the same position.
We'll have to reallign all objects on those three photos, and probably also crop some parts.
And what if the tops of the threes are leaned in one direction on one photo and in the opposite direction on other two photos? How can we allign threes leaned in different directions? We can't. Not to mention a car that moved 3 meters in a split of a second!

Those tutorials also say you absolutely must take photos having your camera fixed on tripod.

Well, here's how to create a nicely dramatic photo without needing the EAB function on your camera, without having to hastily fiddle with aperture times, and without necessarily having to use a tripod.

I'll use as example a photo taken from a bench in park yesterday.
No tripod was used at all and my Nikon D3100 hasn't EAB function either.

Click on the miniature to enlarge it.

In order to create an HDR photo we need to shoot in RAW format.
Most of the DSLR Nikon cameras come with NEF (RAW) Processing feature, under RETOUCH MENU tab.

We use such feature to create two JPEG copies of our photo with modified EV value each.
Note: you can't modify the EV value directly on a JPEG photo. That's why we need to shoot in RAW format for this experiment.

Here's how the first jpeg looks like after I modified the original EV value using NEF (RAW) Processing feature.

Once we have two different jpeg files: one darker and one brighter, we transfer them onto PC and open in Photoshop.

I use Photoshop 7 that hasn't MERGE TO HDR feature so I will have to use VECTOR MASK and BLENDING OPTIONS to achieve the desired effect.

In Photoshop I open the two photos, select and copy the darker photo and paste it on top of the brighter photo to have 2 layers as shown here, on the left.

Then I apply VECTOR MASK on the "darker photo" layer as seen on this screenshot.

This is how the layer looks now.

With the upper layer still selected I right-click on it to play with the BLENDING OPTIONS and chose from dropdown menu any option that pleases me.
Linear Burn and Luminosity are the ones I found the most interesting while working on this photo with tall trees.

Another way to achieve more dramatic effect might be by adjusting CONTRAST and BRIGHTNESS.

Remember to always click on the correct THUMBNAIL on the upper layer before adjusting CONTRAST or BRIGHTNESS.
There are 2 thumbnails on that layer:
- photo thumbnail
- mask thumbnail (white rectangular)

Once it's done I click on MASK thumbnail, pick the brush tool, and having black colour selected as foreground, I start to PAINT-OUT the trees and all the rest making thus the "brighter photo" layer visible from beneath, except the sky. Basically, I make a "HOLE" in the "darker photo" masked layer.

This effect was achieved by playing with CONTRAST and BRIGHTNESS.

And this effect was possible thanks to Luminosity option under BLENDING OPTIONS drop-down menu.